Mobile device based multi-analyte testing analyzer for use in medical diagnostic monitoring and screening

ABSTRACT

A mobile device based multi-analyte testing analyzer for use in medical diagnostic monitoring and screening, and a method of manufacturing the same are disclosed. A reflectance based, colorimetric test strip reader for use with a mobile device having a jack plug receiving socket, said test strip reader adapted for removably receiving a test strip having a test strip longitudinal axis, comprising a housing; a jack plug operably coupled to and extending from said housing and adapted for operable coupling with said jack plug receiving socket; a test strip adapter including structure defining a test strip receiving channel; a light source oriented within said housing for directing light toward said test strip receiving channel to illuminate a test strip arranged within said test strip adapter; and a light sensor oriented within said housing to sense light reflected from a test strip carried by said test strip receiving channel.

FIELD OF THE INVENTION

The invention relates generally to bodily fluid testing systems, andmore particularly to a mobile device based multi-analyte testinganalyzer for use in medical diagnostic monitoring and screening.

BACKGROUND OF THE INVENTION

Bodily fluid testing systems can be used to detect various analyteconcentrations within a bodily fluid sample to provide accurate anddetailed medical information. Such information can be used to aid in thediagnosis and/or treatment of certain medical conditions such asdiabetes. For example, in diabetic monitoring applications, analyzerscan be used by diabetic patients or physicians to detect high (i.e.,hyperglycemia) or low (i.e., hypoglycemia) blood glucose levels. Themonitored levels can aid in the treatment and management of diabetes bynotifying a user of abnormal levels, which allows the user to makenecessary adjustments such as increasing sugar or insulin intake tostabilize blood glucose levels. As another example, HbA1c, which is alsoreferred to as glycated hemoglobin, is an analyte used for bothmonitoring and screening of diabetes, as it captures the average plasmaglucose concentration over prolonged periods. Other examples areanalytes that are more general to other chronic conditions. Suchexamples include lipids (total cholesterol, HDL cholesterol, LDLcholesterol and triglycerides), serum creatinine, hemoglobin andketones, which can be measured in various bodily fluids, such as blood,urine and saliva. Currently, there are several systems and methods usedin medical diagnostic monitoring and screening.

One conventional approach includes the use of a stand-alone test systemto process and analyze data related to analyte concentrations within ameasured sample of a fluid based on a reflectance reading from a reagenttest strip. For example, in U.S. Pat. No. 5,304,468 to Phillips et al.,a method is disclosed for taking a reflectance reading from a reagentpad that consists of a porous matrix. The reflectance reading is basedupon a reflectance change resulting from penetration of the porousmatrix by an aqueous solution. Another method is disclosed in U.S. Pat.No. 6,574,425 to Weiss et al., which uses an “ultra-sensitive” meter (a“reflectometer”) to accurately resolve the full range of developedsubtle color shade changes produced by the transdermal extraction ofanalytes.

Some other conventional approaches include the use of integrated systemscomprising a blood glucose monitor and an external processing device fordata management and analysis such as those disclosed in U.S.2013/0276521 to Fuerst et. al, U.S. Pat. No. 7,935,307 to Angelides, andU.S. Published Application No. 20120142084 to Dunne et. al.Additionally, other integrated systems use naked mobile deviceconnections, where, e.g., a rapid diagnostics test (RDT) is performed bygenerating a digital image of an RDT strip using a camera unit andsoftware application running on a mobile device.

Drawbacks to such conventional approaches include the inability toaccurately quantitatively analyze chemistries that have differentreaction color spectra, to accommodate various test strip dimensions orto dynamically update system parameters according to various testingrequirements. Thus, there is a need for an affordable and cost effectivesystem that can perform an array of color analyses while being universalin design to accommodate various testing requirements.

SUMMARY OF THE INVENTION

The invention is generally directed to a system and method of measuringanalyte concentrations in bodily fluids using a mobile deviceapplication as a user interface to control and process data from areflectance based, colorimetric test strip reader.

One aspect of the invention is directed to a reflectance based,colorimetric test strip reader for use with a mobile device having ajack plug receiving socket, said test strip reader adapted for removablyreceiving a test strip having a test strip longitudinal axis, comprisinga housing; a jack plug operably coupled to and extending from saidhousing along a jack plug axis and adapted for operable coupling withsaid jack plug receiving socket; a test strip adapter operably,removably coupled to said housing, said test strip adapter includingstructure defining a test strip receiving channel presenting a teststrip receiving channel axis; a light source oriented within saidhousing for directing light toward said test strip receiving channelwhen said test strip adapter is operably coupled to said housing suchthat a test strip, when carried by said test strip receiving channel, isilluminated; and a light sensor oriented within said housing to senselight reflected from a test strip carried by said test strip receivingchannel.

A related aspect of the invention is directed to a method of measuringanalyte concentrations utilizing a reflectance based colorimetric teststrip reader operably coupled with a mobile device, the methodcomprising receiving a bodily fluid sample on said test strip;activating a light source to illuminate a reaction area of a test stripin response to insertion of a test strip into a test strip receivingchannel; determining an analyte concentration of said bodily fluidsample based on a color profile change of said test strip; andtransmitting a signal corresponding to said analyte concentration tosaid mobile device.

Another aspect of the invention is directed to a method of using a teststrip reader communicably coupled with a mobile device, the test stripreading having a housing, a jack plug, a test strip adapter including atest strip receiving channel, and an optical sub-system, the methodcomprising activating a light to illuminate a reaction area of a teststrip in response to insertion of a test strip into the test stripreceiving channel; illuminating a reaction area of said test striputilizing a light source of said optical sub-system; detecting a bodilyfluid sample deposited on said test strip; determining an analyteconcentration of said bodily fluid sample based on a color profilechange of said test strip; and transmitting a signal corresponding tosaid analyte concentration to said mobile device.

A still further aspect of the invention is directed to a methodcomprising providing a test strip reader to a user, the test stripreader including a housing, a jack plug, a test strip adapter and anoptical sub-system; and providing instructions to the user forperforming an analyte analysis test with the test strip reader, theinstructions comprising coupling the test strip reader to a mobiledevice; inserting a test strip into an adapter channel of said teststrip adapter; receiving a bodily fluid sample on said test strip;causing said test strip reader to measure an analyte concentration ofsaid bodily fluid sample; and causing said test strip reader to transmitdata corresponding to an analyte concentration to said mobile device fordisplay on a graphical user interface.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention may be more completely understoodin consideration of the following detailed description of variousembodiments of the invention in connection with the accompanyingdrawings, in which:

FIG. 1 depicts a test strip reader in use with a mobile device accordingto an embodiment.

FIG. 2A depicts a perspective view of a test strip reader according toan embodiment.

FIG. 2B depicts a perspective view of the test strip reader of FIG. 2Aaccording to an embodiment.

FIG. 2C depicts a perspective view of the test strip reader of FIG. 2Aaccording to an embodiment.

FIG. 3A depicts an isometric view of a test strip adapter according toan embodiment.

FIG. 3B depicts a underside view of a test strip adapter according to anembodiment.

FIG. 4A depicts a top plan view of an optical sub-system according to anembodiment.

FIG. 4B depicts an isometric view of an optical sub-system according toan embodiment.

FIG. 4C depicts a perspective view of an optical sub-system according toanother embodiment.

FIGS. 5A-5B depict an example of a colorimetric test strip used tomeasure an analyte concentration by causing a color reaction that ismeasured by the test strip reader.

FIGS. 6A-6B depict an example of a mock test strip for use indevice-to-device compensation according to embodiments.

FIGS. 7A-7B depict schematic views of LED circuits according to twoembodiments.

FIG. 8 depicts a schematic view of a sensor circuit according to anembodiment.

FIG. 9 depicts examples of graphical user interfaces according to anembodiment.

FIG. 10 depicts a flow diagram of a communication sequence between thetest strip reader and a mobile device for use in an embodiment.

FIG. 11 depicts a flow diagram of a communication sequence between thetest strip reader and a mobile device for use in an embodiment forstoring device specific compensation data.

FIG. 12 depicts a flow diagram of a process for device-to-devicecompensation according to an embodiment.

While the various embodiments of the invention are amenable to variousmodifications and alternative forms, specifics thereof have been shownby way of example in the drawings and will be described in detail. Itshould be understood, however, that the intention is not to limit theinvention to the particular embodiments described. On the contrary, theintention is to cover all modifications, equivalents, and alternativesfalling within the spirit and scope of the inventions as may be claimed.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description should be read with reference to thedrawings in which similar elements in different drawings are numberedthe same. The drawings, which are not necessarily to scale, depictillustrative embodiments and are not intended to limit the scope of theinventions as claimed.

Embodiments herein relate to an analyte testing analyzer that interfaceswith a mobile device for use in medical diagnostic monitoring andscreening. In embodiments, the analyte testing analyzer comprises areflectance-based colorimetric test strip reader comprising a modulartest strip adapter. The modularity of the test strip adapter allows thereader to be quickly adapted to support a variety of colorimetric teststrips used in different analyte concentration analysis tests. Thereader further comprises a jack plug arranged at a lower end of thereader and which extends outwardly from the reader to communicativelycouple the reader to the mobile device. Because the reader is simple anddoes not have any user interface such as a screen, an end user willinteract with the reader through an application installed on the mobiledevice.

Moreover, a core function of the reader is to detect changes in thecolor profile of the colorimetric test strips in response to fluidsamples deposited on the test strips utilizing an optical sub-systemhoused within the reader. In embodiments, the optical sub-systemcomprises at least two light emitting diodes (LEDs) and a light sensorarranged in between the diodes. The optical sub-system and test stripreaction pad is optically aligned so that incident light from the LEDsgets reflected from the reaction pad and is detected by the lightsensor. During an analysis, the reader continuously sends raw data (thatincludes the detected color of the test strip's reaction pad as measuredby the light sensor) to the mobile device through the jack plug. Thechange in color is then mapped to the concentrations of one of severalanalyte concentrations in the bodily fluid such as glucose, HbA1c,lipids (total cholesterol, HDL cholesterol, LDL cholesterol andtriglycerides), serum creatinine, hemoglobin and ketones, which arepre-programmed in the software application of the mobile device.

Referring now to FIGS. 1, 2A and 2B, a colorimetric test strip reader 10adapted for coupling with a mobile device 15 is depicted. Althoughdepicted in FIG. 1 as being a mobile phone, mobile device 15 can be anymobile device with programming and computing capabilities such as smartphones, tablets, personal digital assistants (PDA), laptop computers, orother suitable computing devices in various embodiments.

In example embodiments, test strip reader 10 comprises a housing 12, ajack plug 20 that is used to couple test strip reader 10 to mobiledevice 15, and a test strip adapter 14 removably and operably coupled tohousing 12 and configured to receive a test strip 16. Housing 12 cancomprise a top portion 22 and a bottom portion 24 coupled together toform an enclosure for accommodating various components (e.g., opticalsub-system 60, printed circuit boards, power supply, battery, etc.)encased within test strip reader 10. As a result of the portable designof test strip reader 10, housing 12 is sized relatively small (e.g., 63mm (length) by 36 mm (width) by 16 mm (height)) and is preferably formedof a lightweight material such as plastic or other suitable materials.

To accommodate removable insertion of test strip adapter 14, top portion22 of housing 12 can comprise an adapter channel 34 integrally formed intop portion 22 (see FIG. 2B). Adapter channel 34 can comprise agenerally U-shaped structure comprising a plurality of grooves formed inor on an outer edge of channel 34 to receive a corresponding couplingfeature of test strip adapter 14. As stated above, top portion 22 can befixedly or removably coupled to bottom portion 24 utilizing variouscoupling mechanisms such as snap, sliding, or screw engagement.Additionally, because test strip reader 10 is preferably batterypowered, bottom portion 24 can comprise a battery compartment 37integrally formed in a side section of bottom portion 24 that can besized to accommodate a single battery unit (see FIG. 2C). The batterycompartment 37 can be closed with battery cover 38 that snaps into thehousing 12 to stay in place.

As illustrated in FIG. 2B, removal of test strip adapter 14 from adapterchannel 34 provides access to an optical window 30 that covers theoptics of test strip reader 10 and a strip switch 32. In embodiments,optical window 30 can be formed in or on an optical cavity 36 arrangedwithin adapter channel 34. Optical window 30 can comprise a generallycircular, rectangular, or oval shape or some other suitableconfiguration in various embodiments. It should be noted, however, thatthe geometrical structure of optical window 30 is sized such thatsufficient light is transmitted from light sources 62 to a reaction areaof test strip 16 and back to the light sensor 66. Furthermore, insertionof test strip adapter 14 into adapter channel 34 aligns an opticalaperture 26 above optical window 30 (refer, e.g., to FIG. 2A), such thata light path is defined which directs light from and back to an opticalsub-system 60 (see FIGS. 4A, 4B and 4C).

In embodiments, strip switch 32 can be arranged proximate a base ofoptical cavity 36 and can comprise a roller lever arm toggle microswitch, an optical path detection switch, or other suitable switches.Strip switch 32 is arranged such that activation of strip switch 32occurs upon insertion of test strip 16 into guiding rails 40 and 42. Inother words, engagement of test strip 16 to strip switch 32 electricallycouples the power supply of test strip reader 10 to light sources 62 andother electronic components of the test strip reader 10, therebypowering it on. In other embodiments, the test strip reader 10 can bepowered on through a different mechanism and the status of strip switch32 can be read by a microcontroller of test strip reader 10 and sent tomobile device 15 for interpretation by the mobile device application ordisplay on a user interface.

Jack plug 20 can be arranged at a distal end of housing 12, such that aportion of jack plug 20 extends outwardly and away from housing 12 alonga jack plug axis 21 to provide connectivity to mobile device 15. Asillustrated in FIGS. 1 and 2A, jack plug axis 21 can be generallyaligned with test strip receiving channel 25 such that insertion of atest strip 16 into channel 25 coaxially aligns a longitudinal axis ofthe test strip with jack plug axis 21, which minimizes the potentialmotion of test strip reader 10 as the test strip 16 is inserted.Although generally referred to herein as “jack plug,” jack plug 20 caninclude any wired or wireless communication element including, but notlimited to, universal serial bus (USB), including micro USB and miniUSB, BLUTOOTH® wireless communication using short-wavelength ultra highfrequencies waves, near field communication (NFC), or WLAN (any IEEE802.11 variant).

In embodiments, test strip adapter 14 can be arranged at a proximal endof housing 12 opposite that of jack plug 20 and can be removably coupledto housing 12. Test strip adapter 14 is configured with a modular designthat allows the unit to accommodate a variety of test strip dimensionsand sizes. The modularity of test strip adapter 14 is a unique featurein comparison to other standard devices, and allows for test stripreader 10 to be easily adapted to support a multitude of colorimetrictest strips by simply reconfiguring test strip adapter 14 to accommodatenew strip dimensions. In addition, test strip adapter 14 can comprise atest strip receiving channel 25 and at least one optical aperture 26arranged within test strip receiving channel 25 which will be discussedin greater detail with reference to FIGS. 3A and 3B.

While particular exemplary embodiments of test strip reader 10 are shownand described herein, it should be understood that the size, shape,and/or particular arrangement or number of components of test stripreader 10 may vary according to various embodiments. For example, inother embodiments, test strip reader 10 can further comprise atemperature sensor arranged within housing 10 to sense and monitor theambient air conditions of test strip reader 10. This ambient temperaturedata can also be sent to mobile device 15 for monitoring, andappropriate information can be displayed on the user interface of mobiledevice 15, for instance, if the ambient temperature is outside of acertain allowable range.

Referring to FIGS. 3A and 3B, a front and rear view of test stripadapter 14 is shown according to an embodiment. As depicted, test stripadapter 14 can comprise a first test strip guiding rail 40 coaxiallyaligned with a second test strip guiding rail 42 to define a test stripreceiving channel 25 for accommodating test strip 16. As depicted inFIG. 3A, in embodiments, the strip guiding rail 42 may further include asmall notch 43 (e.g., a bridge feature) to help secure placement of teststrip 16 in the z-axis direction, but may vary in other embodiments. Inother embodiments, for example, the strip guiding rail 42 can beconfigured without notch 43 or may be integrally formed with guidingrail 40 to include two or more notches 43 to accommodate various adapterconfigurations. In addition, as discussed with reference to FIG. 2A,test strip adapter 14 can comprise at least one optical aperture 26,formed in or on test strip receiving channel 34. FIG. 3B illustrates theunderside view of test strip adapter 14 comprising optical aperture 26,first test strip guiding rail 40, secondary underside test strip guidingrails 41, a test strip stopping block 50 and test strip 16. Guidingrails 40, 41, 42 and test strip stopping block 50 in conjunction allowtest strip 16 to be inserted in a repeatable manner into test stripreader 10. In various embodiments, the positioning and dimensions oftest strip adapter 14 and its corresponding components (e.g., guidingrails 40, 41, 42 and stopping block 50) can be modified to allow for theuse of strips 16 of different dimensions. Specifically, a change in thewidth or thickness of test strip 16 would induce changes in guidingrails 40, 41, 42, while a change in the distance from the front of teststrip 16 to its reactive area would induce a change in the position ofstopping block 50. For example, in the embodiment of FIG. 3B, stoppingblock 50 can accommodate strips of various lengths without modificationsto its position, as long as the length of test strip 16 is larger than acertain minimum.

Referring to FIGS. 4A, 4B and 4C, an optical sub-system 60 of test stripreader 10 is depicted according to an embodiment. In embodiments,optical sub-system 60 can comprise an optical block 67 arranged on asupport structure 63. In embodiments, support structure 63 can comprisea circuit board, such as a printed circuit board (PCB), or any othersuitable base structure. Additionally, it can be advantageous to sizethe geometrical dimensions of support structure 63 such that supportstructure 63 is configured for fitted insertion into housing 12. Variouscoupling mechanisms can be used for attaching support structure 63 tohousing 12. For example, in one embodiment, support structure 63 cancomprise at least one mounting hole 65 (see FIGS. 4A and 4B) foraccommodating screw or other fasteners to secure support structure 63 tohousing 12. In other embodiments, such as that of FIG. 4C, othercoupling mechanisms can be used including, but not limited to adhesivebonding, snap connects, clamps, or brackets. The depictions of opticalsub-system 60 in FIGS. 4A, 4B and 4C are not to scale and are simplyused to illustrate basic components and features of embodiments ofoptical sub-system 60. For example, the depiction of optical sub-system60 in FIG. 4C is shown without body member 61 to better illustratecomponents such as reflective surfaces 68, light sources 62 and lightsensor 66, which are discussed in further detail below.

In embodiments, optical block 67 can comprise a body member 61comprising a generally L-shaped that defines a mounting channel 55within a cross-sectional area of body member 61 to accommodate placementand/or mounting of components such as light source 62, light sensor 66,and reflective surfaces 68. For example, as depicted, optical sub-system60 can include at least one reflective surface 68, at least oneilluminating light source 62 arranged proximate reflective surfaces 68,and at least one light sensor 66.

As illustrated in FIGS. 4A and 4B, in embodiments, optical block 67 canfurther comprise a sensor well 64 arranged intermediately betweenreflective surfaces 68 at an end opposite the placement of light sources62. This particular arrangement of sensor well 64 can be advantageous inselectively controlling the amount of light received within sensor well64. In embodiments, light source 62 can comprise a light-emitting diodecoupled to a bracket 72 to ensure proper alignment of light source 62with reflective surfaces 68. Bracket 72 can be coupled to or arranged inapposition to each frame 74 of reflective surfaces 68 (see FIGS. 4A, 4Band 4C). While depicted in this embodiment as an LED, it should be notedthat light source 62 can include any device capable of illuminatinglight onto a surface of an object.

To detect light illuminated from light source 62, light sensor 66 can bearranged within optical sub-system 60, such that light reflected fromtest strip 16 is directed to sensor 66. In embodiments, light sensor 66can be coupled to or arranged on support structure 63 and can be sizedto fit within sensor well 64 as illustrated in FIG. 4A. Sensor 66 cancomprise a photodiode, optical detector, phototransitors,photoresistors, or other suitable sensing elements in variousembodiments. As discussed previously, the structural layout of opticalsub-system 60 serves to illuminate the test strip 16 being imaged byusing light sources 62 in conjunction with the inclined reflectivesurfaces 68 that direct the light at the reactive area of test strip 16.Some of the light reflected off test strip 16 can travel inside of lightsensor well 64 where it eventually can get detected by the light sensor66. This design minimizes the effect of specular reflection because ofthe mismatch between the incident angle of illumination onto thereactive area of test strip 16 and the angle between that reactive areaand light sensor 66. This allows mostly diffuse reflected light to reachlight sensor 66, which is known to be the type of light that carries theinformation about the surface color of the reactive area of test strip16.

In embodiments, reflective surfaces 68 can comprise a reflectiveelement, such as a mirror affixed to body member 61 or an angled frame74. Although the depicted embodiments of FIGS. 4A, 4B and 4C illustratesframe 74 as being oriented at an approximately 25-degree angle from theplane of the support structure 63, other suitable angular geometries canbe employed, such as, e.g., 15-45 degrees. In particular, the angularconfiguration of body member 61 or frame 74 can be adjusted according toa desired illumination path from light source 62 to test strip 16. Inother words, the total distance of the illumination path, which canrange from approximately 10 to 30 mm in length in other embodiments,when projected on a two-dimensional plane, can be increased or decreasedrelative to the angular configuration of body member 61 or frame 74. Theillumination path of light source 62 can be further defined based on theplacement and/or arrangement of reflective surfaces 68. For example, inthe embodiments of FIGS. 4A, 4B and 4C, reflective surfaces 68 areequidistantly and angularly displaced from one another, thereby creatinga generally triangular illumination path, while in other embodimentsthis particular configuration may vary.

In addition, the type of geometry described above which features, inparticular, reflective surfaces 68 at an angle relative to the directedlight by light sources 62 and light sensor 66 allows the use of highluminosity and efficient through-hole light source components, such asthrough-hole LEDs. These types of LEDs allow for light of a highluminosity to be directed in a precise manner at the test strip 16 beinganalyzed, while being more efficient in their battery use, causing lessheat dissipation and being more cost effective than comparableboard-mounted components. This also allows for a more compact design ofthe device. Moreover, the geometrical arrangement of reflective surfaces68 allows for the use of multiple light sources 62 of different centralwavelengths and luminosities. This can be particularly advantageous inthat each light path of light sources 62 can have identical geometriesfrom the light source 62 to the test strip 16 and in return to the lightsensor 66, which facilitates the design of the device and the analysisalgorithms in the application software of mobile device 15.

The exemplary embodiments of FIGS. 4A, 4B and 4C are for illustrationpurposes only and the arrangement and/or configuration of opticalsub-system 60 can vary in other embodiments specific to applicationand/or system requirements. For example, as depicted in FIG. 4C, thearrangement of reflective surfaces 68 allows for more illuminating lightsources 62 of different wavelengths to be present.

Referring to FIGS. 5A and 5B, a colorimetric test strip 16 is depictedfor use with the test strip adapter 14 in an embodiment of theinvention. One example of such a test strip 16 is the BETACHEK® G5 teststrip. In embodiments, test strip 16 includes a substrate 106 having athrough hole 110 that is located substantially in the same locationrelative to an insertion end 102 as the reactive zone 104. Materials fora reactive zone 104 are disposed on a proximal face 108 of thecolorimetric test strip 16 over the through hole 110, and are accessiblefrom a distal face 112 of the colorimetric test strip 16 through thethrough hole 110. When the colorimetric test strip 16 is fully insertedin the test strip adapter 14, the through hole 110 is in alignment withthe optical aperture 26 on the test strip adapter 14 and is accessiblefrom the distal face 112. The alignment between the optical aperture 26and the through hole 110 allows for the bodily fluid sample under testto be deposited onto the reactive area 104 of the proximal face 108 ofthe colorimetric test strip 16 after insertion into the test stripreader 10.

The colorimetric strips of FIGS. 5A and 5B are representative of atwo-sided strip wherein the bodily fluid (e.g., a blood droplet) isapplied to one side and the reactive change is observed on the other.When two-sided strips are utilized, the firmware controlling test stripreader 10 can be programmed by the software application controlling themobile device 15 to observe the onset of the color change in atime-lapsed fashion and to acquire the reflected color signal of thereactive segment of the two-sided strip at a predetermined time intervalafter the onset. The digital signal acquired at the predetermined timeinterval can then be analyzed to provide the test results. Thepredetermined time can be established at a time period known to providerepeatable results, thereby enhancing the accuracy and reliability ofthe measurement.

In other embodiments, a single sided test strip 16 can be used thatallows for the bodily fluid under test, which in some cases can comprisea bodily fluid sample pre-mixed with a reagent, to be applied directlyto the reactive zone 104. Once the fluid sample is applied, the reactivezone 104 develops a color, which can then be detected after test strip16 is inserted into the test strip reader 10. In this embodiment, teststrip 16 is designed such that test strip 16 is inserted into test stripreader 10 only after the fluid sample is applied to the test strip.Similar colorimetric test strips are described in U.S. PatentApplication Publication No. 2014/0072189, disclosures of which areincorporated by reference herein.

Referring to FIGS. 6A and 6B, a mock test strip 200 is depicted for usein the device-to-device compensation procedure of test strip reader 10,which is discussed with reference to FIG. 12. Each unit of test stripreader 10 has small variations in the performance of its individualcomponents, such as the light sources 62, light sensor 66, reflectivesurfaces 68, as well as small manufacturing variations in the geometryof its housing 12, test strip adapter 14 and body member 61. Thesevariations cause a change in the signal observed by light sensor 66across different manufactured units, which can be compensated by one orseveral mock test strips 200. In embodiments, a mock test strip 200 cancomprise a substrate 202, a reference material 204 with one side with acolor area 206 printed with a known color that is visible through anaperture 208 formed in substrate 202. In another embodiment, mock teststrip 200 can comprise substrate 202 solely, which is of a known color.In that case, no reference material 204 or aperture 208 is necessary, asthe substrate itself is used as the material of known color.

Referring to FIGS. 7A and 7B, a schematic view of a LED circuit 310 isdepicted according to two embodiments. In one embodiment, LED circuit310 can comprise a supply voltage 312, a current setting resistor 314,which together power a LED 316. LED 316 is toggled between an off and onstates using a modulating signal 318, which is connected to a groundpotential through a resistor 320, and that is applied to a gate terminalof a FET transistor 319 to control the FET transistor 319. This allowsthe effective brightness of LED 316 to be adjusted through pulse-widthmodulation (PWM) by rapidly switching LED 316 on and off at differentrates. In other embodiments, referring now to FIG. 7B, LED circuit 310can comprise a supply voltage 352, a constant voltage source 357, acurrent setting resistor 354, which together power a LED 356. Althoughnot depicted in FIGS. 7A and 7B, in still other embodiments, the LEDcircuit 310 can be activated by strip switch 32 as previously discussed,which detects the presence of test strip 16. Such an arrangement isadvantageous in that it assures test strip 16 is properly secured intest strip receiving channel 25 before an analysis is performed. Thearrangement can also prevent inadvertent activation of light sources 62,which in turn helps to the amount of power consumed by test strip reader10

Referring to FIG. 8, a schematic view of a light sensor circuit 400 isshown according to an embodiment. In this embodiment, light sensorcircuit 400 can comprise a digital light sensor integrated chip 432,which uses built-in analog photodiode circuits and color filters todetect the level of incoming light at different wavelengths. In thisembodiment, digital light sensor integrated chip 432 communicates to therest of the test strip reader 10 digital values that are proportional tothe amount of light that hits its sensors in wavelength ranges definedby each of its channels' response spectra, over a certain time durationthat is called the integration time. This communication can beaccomplished using the I2C communication protocol using I2C pins 434.One example of such a digital light sensor integrated chip 432 is theAMS-TAOS TCS3472. In other embodiments, light sensor circuit 400 can bebuilt directly from analog photodiodes, but using a digital integratedchip 432 offers a simpler design that while still includes analogphotodiodes and color filters, is optimized and standardized by themanufacturer of the integrated chip.

Referring to FIG. 9, a set of example user interfaces 540-548 displayedby the mobile device 15 to a user during the analyte testing process isshown. In one embodiment, at the start of an analyte test sequence, theuser is shown a test strip calibration code selection screen 540. Afterconfirming this code, the user is requested to connect test strip reader10 to mobile device 15 with screen 541. Following this, the user isrequested to insert test strip 16 in screen 542. Next at screen 543, theuser is requested to apply a bodily fluid sample to test strip 16. Oncea bodily fluid sample is received, the mobile device 15 interfacenotifies the user that the analysis is in progress with screen 544, andupon completion of the test, the user is presented with an analyteconcentration reading in screen 545.

In addition, a user interface can comprise a plurality of error screens,such as error screens 546-548 to provide warning and error messages to auser utilizing mobile device 15. In particular, during use, an errormessage may occur that will cause either the analyte test sequence tostop running or warn a user that an error has occurred. For example,error screens 546 and 548 provide warning messages to a user, but do notprevent the analyte test sequence from being completed. In contrast, anerror message received on screen 547 will cause the application onmobile device 15 to quit, thereby preventing a user from completing theanalyte test sequence until the problem causing the error is rectified.

In operation and referring now to FIG. 10, a flow diagram of a typicalcommunication sequence 600 between mobile device 15 and test stripreader 10 when performing an analyte test sequence is illustrated. Whentest strip reader 10 is powered on at 602, it can continuously send a“HELLO MESSAGE” to mobile device 15 via a communication port such as,e.g., the audio jack port of mobile device 15 as illustrated inembodiments herein. This “HELLO MESSAGE” can contain a device serialnumber, device diagnostic information, the device software versionnumber and device specific compensation data that has been previouslystored in the device's non-volatile memory. This compensation data isdescribed in further detail below. After mobile device 15 receives this“HELLO MESSAGE”, at 604, it can send a “CONFIGURATION MESSAGE” thatcontains a blinking sequence that test strip reader 10 can use toanalyze colorimetric test strip 16 (refer, e.g., to FIG. 1) that isinserted into test strip reader 10.

In one embodiment, this blinking sequence can either use a single lightsource 62, in which case it can specify the luminosity of the lightsource when turned on (for instance via a pulse-width modulation dutycycle parameter), the period of time elapsed between successive lightsources blinks, the duration that the light source stays on during ablink and light sensor 66 parameters such as its electronic gain andintegration time. In another embodiment, this blinking sequence can usea plurality of light sources 62, in which case it can specify theparameters as listed above, but for each of the light sources 62, inaddition to the order in which light sources 62 should blink. As analternative to continuously powering on light sources 62, the blinkingsequence as described above can be used as a power consumption reductiontechnique to minimize the battery use of test strip reader 10, whilestill sampling in time the color of the reaction area of test strip 16inserted into test strip reader 10.

Different blinking sequences can be configured for different stages ofthe analyte test sequence, different test strip manufacturing lots anddifferent test strip types (for different analytes) using a test stripcode number. In one embodiment, the blinking sequences can correspond toa test strip code number and can be permanently stored in theapplication software or as a file on mobile device 15. In anotherembodiment, files with the blinking sequences can be stored on teststrip reader 10 and transferred to mobile device 15 as needed. In yetanother embodiment, a file containing the blinking sequences can bedownloaded from a server via the internet by mobile device 15 whenneeded based on the test strip type and a test strip code number usingfor instance Wifi or cellular internet networks. This embodiment offersthe advantage of allowing the manufacturer to update the blinkingsequences as needed remotely, namely, light sensor 66 parameters such aselectronic gain and integration, as well as the effective brightness oflight sources 62, which offers more stability with respect to thecharacteristics of light sensor 66, light source 62 components and teststrips 16 that can vary between different manufacturing lots. Moreover,the blinking sequence downloading feature allows new manufacturing lotsof test strips 16 to be supported after test strip reader 10 isdispatched to the user because it only requires that a file containingthe new blinking sequences be downloaded by mobile device 15. Otherparameters such as the allowed ambient temperature range and permittedbattery voltage values can also be updated remotely in this manner.

In addition, the modularity of the definitions of the blinking sequencesallows the possibility of adding support for testing of new analyteswith an over-the-air or physical software update to mobile device 15software without having to change the software on test strip reader 10,which is usually a complex task for users to perform for such embeddeddevices. These over-the-air software updates can also include completelynew algorithms that would be needed to analyze the kinetic or end-pointreactions of test strips 16 for the new analytes. Since test stripreader 10 can contain a plurality of light sources 62 that can havedifferent central wavelengths, it is particularly suitable for theanalysis of multiple types of analytes, including new ones that areconceived after test strip reader 10 is delivered to the user.

Next in communication sequence 600, at 605, once test strip reader 10receives the “CONFIGURATION MESSAGE”, it can then configure itself withthe specified blinking sequence, replying with a “CONFIGURATIONACKNOWLEDGEMENT” to mobile device 15 when this process is done. Teststrip reader 10 can then go through the blinking sequence as specified.Following each blink in the blinking sequence, at 606, test strip reader10 can send “COLOR SENSOR DATA” which it measured during that blink.This “COLOR SENSOR DATA” can contain the sensor data values {I_(c)} fromone or several color channels c of light sensor 66 of test strip reader10, device diagnostic information such as the ambient temperature andbattery level, an identification of the light source used in thisparticular blink and a sequence number that grows sequentially with eachsuccessive “COLOR SENSOR DATA” to allow detection any potential loss ofdata by the mobile device's application software.

Mobile device 15 receives this “COLOR SENSOR DATA” and can process itaccording to algorithms defined in its corresponding software to analyzethe color reaction of test strip 16 inserted into test strip adapter 14of test strip reader 10. This can include giving the user feedbackthrough the screen, audio output or vibration motor of mobile device 15about the progress of the analysis, or any errors such as for example anambient temperature out of range or low battery.

At any point during the analysis, illustrated at 604 in FIG. 10, mobiledevice 15 can send a new “CONFIGURATION MESSAGE” to test strip reader 10with a new blinking sequence that test strip reader 10 should use. Thisfeature can be used to allow to optimize the battery use of test stripreader 10 by using a faster blinking sequence, meaning with a lowerperiod of time between successive blinks, only at specific points in thecolor reaction of the test strip when it is necessary to measure thecolor reaction with more time granularity.

Once mobile device 15 has received enough “COLOR SENSOR DATA” from teststrip reader 10 that fully defines the kinetic or end-point colorreaction of the test strip 16 that it is analyzing, the application onmobile device 15 can compute and show the analyte concentration readingto the user on mobile device 15 screen. In another embodiment, mobiledevice 15 can send this reading to another software application onmobile device 15, or send it through the internet to a server that canstore this data.

At 608, mobile device 15 can then send a “SLEEP COMMAND” that test stripreader 10 answers with a “SLEEP ACKNOWLEDGEMENT” before going to a deepsleep mode in order to save battery power. In an embodiment, at anypoint in this sequence the test strip reader 10 can be powered off bytoggling strip switch 32 utilizing the same methods as discussed withreference to FIG. 2B.

Referring to FIG. 11, a method 700 for storing device specificcompensation data for the test strip reader 10 utilizing mobile device15 is depicted. Storing of this device specific compensation data oftest strip reader 10 can occur during the manufacturing process or canbe performed by an end user.

At 702, after test strip reader 10 is powered on, it can continuouslysend a “HELLO MESSAGE” to mobile device 15 via a communication port ofmobile device 15. After mobile device 15 receives the “HELLO MESSAGE”,then at 704 it can send test strip reader 10 a “CALIBRATION MESSAGE”that contains new device specific compensation data that test stripreader 10 should store in its non-volatile memory. At 705, test stripreader 10 receives this “CALIBRATION MESSAGE” and answers with a“CALIBRATION ACKNOWLEDGEMENT” once it has stored this device specificcompensation data in its non-volatile memory. Test strip reader 10 at706 then goes back to continuously sending a “NEW HELLO MESSAGE” thatcontains the new device specific compensation data that it stored in itsnon-volatile memory. Next at 708, mobile device 15 can then send a“SLEEP COMMAND” that test strip reader 10 answers with a “SLEEPACKNOWLEDGEMENT” before going to a deep sleep mode in order to savebattery power. In an embodiment, at any point in this sequence teststrip reader 10 can be powered off by toggling its strip switch 32. Asdiscussed with reference to FIG. 2B, in one embodiment, strip switch 32is toggled by the removal of a test strip 16 from test strip adapter 14.

Referring to FIG. 12, a method 800 for characterizing the opticalcharacteristics of a given device by generating and storingdevice-to-device compensation data in the device's non-volatile memoryis depicted for use in an embodiment. The characterization method 800can be used to compensate for small variations in the performance ofindividual components of test strip reader 10, such as the light sources62, light sensor 66, reflective surfaces 68, as well as smallmanufacturing variations in the geometry of the plastics of test stripreader 10.

At the first step 822, the characterization application can be launchedon mobile device 15. Next at step 824, test strip reader 10 can beconnected to mobile device 15. Once an acknowledgement is received inthe user interface of mobile device 15, then at 826, a mock test strip200 with a color area 206 of known constant color can be inserted intotest strip reader 10. In an embodiment, this insertion toggles stripswitch 32 and powers on test strip reader 10, which causes it to enterstep 702 as discussed with reference to FIG. 11, and to continuouslysend a “HELLO MESSAGE” to mobile device 15.

At step 828, utilizing the user interface of the characterizationapplication running on mobile device 15, an algorithm, which utilizes afunction to determine device specific compensation data, is initiated.This in turn causes the software on mobile device 15 to configure teststrip reader 10 with a “CONFIGURATION MESSAGE” that contains a blinkingsequence as described above with reference to FIG. 10. Upon receipt ofthe “CONFIGURATION MESSAGE,” test strip reader 10 will then beginsending “COLOR SENSOR DATA” according to the blinking sequence it hasbeen configured to use. As previously discussed, “COLOR SENSOR DATA” caninclude sensor data values {I_(c)}, device diagnostic information, lightsource identification information, as well as other relevant devicestatus data. After the software on mobile device 15 receives one orseveral such “COLOR SENSOR DATA”, mobile device 15 will compute thedevice specific compensation data for the mock test strip that was used.This process can be repeated with several different mock strips ifrequired to compute the full compensation data across different mocktest strip colors. This set of different mock test strips can bedesigned to span the reflected colors that the test strip reader willsee during various analyte testing.

During device characterization, test strip reader 10 can be configuredas either a reference “master” unit or a regular “production” unit. Forexample, if test strip reader 10 used in the device characterizationmethod 800 is a reference “master” unit, the resulting compensation datais referred to as the reference compensation data {M_(s,p)}. Thisreference compensation data {M_(s,p)} for each mock test strip s and foreach set of imaging parameters p can be stored for later use by mobiledevices 15 when performing analyte test sequences. In one embodiment,this reference compensation can be included in the application softwaredistributed on mobile device 15 used during future analyte testsequences. In another embodiment, this reference compensation data canbe stored in a file on a server that can be accessed by mobile device 15during an analyte test sequence via the interne using Wifi or mobilecellular networks. Allowing mobile device 15 to retrieve this referencecompensation data remotely allows the reference “master” unit used bythe manufacturer to collect master compensation data to be changedwhenever needed, which reduces the dependency on a single “master” unitthat needs to be safeguarded over the lifetime of the product.

The imaging parameters p can include the light source 62 to be used, theeffective brightness of the light source 62 when turned on, the durationthat the light source 62 stays on during a blink, and light sensor 66parameters such as its electronic gain and integration time. In oneembodiment, the reference compensation data {M_(s,p)} can consist simplyof light sensor values recorded by light sensor 66 for each mock teststrip s and for each set of imaging parameters p when measuring thecolor area 206 of known constant color of mock test strip 200.

Contrarily, if test strip reader 10 used in the device characterizationmethod 800 is a regular “production” unit, the resulting compensationdata is referred to as the device specific compensation data {D_(s,p)}.This device specific compensation data {D_(s,p)} for each mock teststrip s and for each set of imaging parameters p can be sent to teststrip reader 10 by mobile device 15 via a “CALIBRATION MESSAGE” asdescribed in step 704 of method 700 for storing device specificcompensation data, which can cause test strip reader 10 to store thedevice specific compensation data in its non-volatile memory. After thisstep, the particular reader is considered calibrated and can be used foranalyte testing. In one embodiment, the device specific compensationdata {D_(s,p)} can consist simply of light sensor values recorded bylight sensor 66 for each mock test strip s and for each set of imagingparameters p when measuring the color area 206 of known constant colorof mock test strip 200. Since the only required material for performingthe device-to-device characterization method 800 on a regular“production” test strip reader 10 unit is the characterizationapplication software to run on the mobile device 15 and one or severalmock test strips 200, this method can be performed both during themanufacturing process and also by an end user if needed.

During a regular analyte test sequence that follows the sequencedescribed in FIG. 10, mobile device 15 software receives a “HELLOMESSAGE” that contains device specific compensation data {D_(s,p)}stored in test strip reader 10's non-volatile memory. For a specific setof imaging parameters p that can be requested by mobile device 15through its “CONFIGURATION MESSAGE”, mobile device 15 software computesa compensation function based on reference compensation data {M_(s,p)}stored in the mobile software or obtained from a remote server aspreviously described, and device specific compensation data {D_(s,p)}received from test strip reader 10 in its “HELLO MESSAGE”. Eachsubsequent light sensor value I_(c,p) for a specific color channel c andset of imaging parameters p received by mobile device 15 from test stripreader 10 in “COLOR SENSOR DATA” can be compensated before use inanalysis algorithms using an equation of the following form to map it tothe equivalent value on the reference “master” unit:I* _(c,p)=ƒ({M _(s,p) }, {D _(s,p) }, I _(c,p))where the compensation function ƒ(.) can be a mathematical function suchas a polynomial, or a look-up table. This equation yields thecompensated light sensor value I*_(c,p), which can then be used insubsequent analysis algorithms as if it was measured using the reference“master” unit. In one embodiment, the compensation function ƒ(.) canhave the simple form:

${f( {\{ M_{s,p} \},\{ D_{s,p} \},I_{c,p}} )} = {\frac{M_{s,p}}{D_{s,p}}I_{c,p}}$where compensation data for a specific mock test strip s is useddepending on which analyte is being tested, and which part of the teststrip color reaction is being analyzed, for a certain set of imagingparameters p.

Use of this simple form is possible because of key elements in thedesign of the test strip reader 10, such as the optical geometry, whichallows the use of high luminosity light sources 62 and directly guide alarge portion of the light from the light sources 62 to the test strip16 being analyzed. Another aspect that contributes to this is the smallform factor of the device that, combined with the optical geometry,minimizes the total projected distance of the light path from the lightsources 62 to the light sensor 66. This design allows for a predictablelinear response of the optical system when imaging test strip reactioncolors close to the known colors the mock test strips used in thedevice-to-device compensation described above, because of an optimalrejection of ambient light and the isolation of other variables such asspread of the light beam with distance, which in turn allows for the useof the simple compensation function listed above and a small number ofmock test strips 200. Using the simplest possible compensation functionis desirable because it will produce the most consistent andreproducible results.

In one embodiment, a test strip reader can be provided to a user in theform of a kit which includes a test strip reader according to any of theembodiments described herein, and a set of instructions for using thetest strip reader as described herein. The kit may comprise one or morehermetically sealed packages that can include test strips 16 for one ormore analytes, the mock test strips 200, lancets, etc. that are neededfor operating and maintaining the test strip reader 10, and performinganalyte testing. The instructions may be provided as part of the kit, orindications may be provided linking a user to electronically accessibleinstructions. The instructions can be any of a variety of tangible orintangible media including, but not limited to a written manual, aseparate screen inside of the application software running on the mobiledevice 15 for analyte testing, a CD or CD-ROM, DVD, BluRay, digitallydownloadable or viewable on onto a personal device, such as a computer,tablet, smart device, and/or via verbal instruction by a provider of thekit. In another embodiment, the instructions are provided, for example,by a manufacturer or supplier of the assemblies, separately fromproviding the assemblies, such as by way of information that isaccessible using the Internet or by way of seminars, lectures, trainingsessions or the like. The kit and/or the separate components of the kitmay be provided by causing the kit and/or components to be manufacturedand made available to a user.

The embodiments above are intended to be illustrative and not limiting.Additional embodiments are within the claims. In addition, althoughaspects of the present invention have been described with reference toparticular embodiments, those skilled in the art will recognize thatchanges can be made in form and detail without departing from the scopeof the invention, as defined by the claims. Persons of ordinary skill inthe relevant arts will recognize that the invention may comprise fewerfeatures than illustrated in any individual embodiment described above.The embodiments described herein are not meant to be an exhaustivepresentation of the ways in which the various features of the inventionmay be combined. Accordingly, the embodiments are not mutually exclusivecombinations of features; rather, the invention may comprise acombination of different individual features selected from differentindividual embodiments, as will be understood by persons of ordinaryskill in the art.

Any incorporation by reference of documents above is limited such thatno subject matter is incorporated that is contrary to the explicitdisclosure herein. Any incorporation by reference of documents above isfurther limited such that no claims that are included in the documentsare incorporated by reference into the claims of the presentApplication. The claims of any of the documents are, however,incorporated as part of the disclosure herein, unless specificallyexcluded. Any incorporation by reference of documents above is yetfurther limited such that any definitions provided in the documents arenot incorporated by reference herein unless expressly included herein.

For purposes of interpreting the claims for the present invention, it isexpressly intended that the provisions of Section 112(f) of 35 U.S.C.are not to be invoked unless the specific terms “means for” or “stepfor” are recited in a claim.

The invention claimed is:
 1. A reflectance based, colorimetric teststrip reader for use with a mobile device having a jack plug receivingsocket, said test strip reader adapted for removably receiving a teststrip having a test strip longitudinal axis, comprising: a housing; ajack plug operably coupled to and extending from said housing along ajack plug axis and adapted for insertion into said jack plug receivingsocket; a test strip adapter having a modular configuration that isadapted to be operably, removably coupled to said housing, said teststrip adapter including structure defining a test strip receivingchannel presenting a test strip receiving channel axis aligned alongsaid jack plug axis when said test strip adapter is coupled to saidhousing, such that said test strip is receivable by said test stripadapter when said test strip adapter is physically and electricallycoupled to said housing with said test strip longitudinal axis coaxialwith said jack plug axis; a light source oriented within said housingfor directing light toward said test strip receiving channel when saidtest strip adapter is coupled to said housing such that said test strip,when carried by said test strip receiving channel, is illuminated, saidlight source including at least two light emitting diodes, which areequidistant from said light source and angularly displaced from oneanother, arranged within said housing each light emitting diodepositioned proximate a corresponding angled reflective surface to directlight from said reflective surface toward said test strip receivingchannel; a light sensor oriented within said housing to sense lightreflected from said test strip carried by said test strip receivingchannel, said light sensor oriented between said at least two lightemitting diodes within said housing to sense light reflected from saidtest strip; and control circuitry configured to receive a controlsequence from said mobile device via the jack plug, control said lightsource in response to said control sequence, continuously generate asignal corresponding to a measured light intensity from said lightsensor during said control sequence, and transmit said signal to saidmobile device for processing.
 2. The test strip reader of claim 1,wherein each of said angled reflective surfaces are inclined at an anglebetween 15-45 degrees relative to a direction defined by a beam of lightemitting from said corresponding light emitting diode to direct lightfrom said reflective surface toward said test strip receiving channelalong a light path from the light emitting diode to the correspondingangled reflective surface to the test strip and back to the light sensorthat is between 10-30 mm in length when projected on a two-dimensionalplane.
 3. The test strip reader of claim 1, wherein said at least twolight emitting diodes comprise a first light emitting diode of a firstcolor and a second light emitting diode of a second color.
 4. The teststrip reader of claim 1, wherein said light source comprises three ormore light emitting diodes.
 5. The test strip reader of claim 1, whereinsaid control sequence includes a blinking sequence that instructs saidcontrol circuit to vary at least one of a blink, a duration, an order,or a luminosity of said at least two light emitting diodes.
 6. The teststrip reader of claim 1 further comprising a strip switch arranged on asurface of said test strip reader, and wherein said strip switch isconfigured to power on said test strip reader upon activation.
 7. Thetest strip reader of claim 1 wherein said control circuitry is furtherconfigured to receive a signal from said mobile device corresponding toa configuration profile, and wherein said configuration profile isdynamically updated to modify parameters of said light source duringsaid control sequence.